@inproceedings{
    address = {New York, NY, USA},
    author = {Hemmert, Fabian and Hamann, Susann and Wettach, Reto},
    booktitle = {TEI '09: Proceedings of the 3rd International Conference on Tangible and Embedded Interaction},
    doi = {10.1145/1517664.1517672},
    isbn = {978-1-60558-493-5},
    location = {Cambridge, United Kingdom},
    month = {February},
    pages = {19--20},
    publisher = {ACM},
    title = {The Digital Hourglass},
    url = {http://dx.doi.org/10.1145/1517664.1517672},
    year = {2009}
}